Stackable fan

ABSTRACT

An air blowing system is disclosed having top and bottom air blowers that each includes a blower base and a blower housing tiltable relative thereto, and a coupling for enabling pivotable affixation of the top blower base to the bottom air blower, The air blowing system has at least first and second operational modes, whereby in the first operational mode the coupling does not affix the top blower base to the bottom air blower and the bottom and top air blowers are relatively independent, and in the second operational mode the coupling pivotably affixes the top blower base to the bottom air blower.

FIELD OF THE INVENTION

This invention relates to household fans and blowers, and more specifically, to a system of stackable fans capable of directing a plurality of cooling breezes into differing directions and portions of a room.

BACKGROUND OF THE INVENTION

There is an ever-increasing need to provide cooling or ventilating air flow at home and in the work place. The most common apparatuses used for satisfying this need are portable axial fans. Axial fans have an electric motor typically oriented such that its rotational axis is aligned with the direction of air movement. A fan blade affixed to the motor's rotor rotates about the axis and causes air to be pushed forwardly from the fan in the direction along the axis. Because the airflow is forced straight forwardly from the fan, axial fans are suited to cooling or ventilating a particular area of a room.

In order to increase the area of a room cooled or ventilated, many axial fans are equipped with means for oscillatory redirection of the airflow in a sweeping pattern. Such an oscillation is typically caused by an elaborate and expensive oscillation gearing system that converts rotational energy from the motor's rotor and causes the orientation of the motor and its rotor to sweep back and forth relative to the environment. Not only are such gearing systems expensive to manufacture, but the multitude of moving parts renders them somewhat short-lived and their parasitic use of the motor's rotational energy reduces the desired airflow from the fan. Energy which could be devoted to causing airflow is diverted to causing the oscillation.

Oscillation is also caused in some axial fans by the use of an additional oscillation motor. Such oscillation motors typically cause a sweeping motion to the entire fan housing relative to its base, thereby causing the exhaust of the fan to move back and forth in an equivalent sweeping motion. In order to obtain an oscillation of sufficient breadth and smoothness, the auxiliary oscillation motors must be somewhat expensive, noisy, and powerful, using relatively high amounts of costly electrical energy that could otherwise be used to increase airflow.

There exists the need for an efficient air blowing apparatus which overcomes the above problems of fans and blowers by providing means for increasing the airflow to a greater area, and such is an object of the invention. There exists the need for an efficient air blowing apparatus that creates simultaneous airflow to a plurality of areas, and such is an object of the invention. There exists the need for an efficient air blowing apparatus that uses all of its consumed energy toward the production of airflow, and such is an object of the invention. There exists the need for an efficient air blowing apparatus that creates simultaneous airflow to various selectable areas, and such is an object of the invention. There exists the need for an efficient air blowing apparatus which can either be used as a single more powerful fan system having a plurality of integral fan units, or as a plurality of less powerful individual and separate fans, and such is an object of the invention. There exists is the need for a modular fan system that enables users to increase the air flow there-from my adding individual fan modules, and such is an object of the invention. There exists the need for such a modular fan system in which all fan modules may be powered from only one power outlet, and such is an object of the invention.

Other needs and objects will become apparent upon a reading of the following disclosure in combination with the appended drawings.

SUMMARY OF THE INVENTION

The present invention is preferably embodied as an axial fan system having two or more fan units which are adapted for use either together in a single adaptable assembly or separately as individual axial fans. When used individually, the fan units may be connected to separate power outlets in remote locations. When used individually, the fan units may be positioned on the floor, on table tops, or mounted to vertical walls and may each be rotated and/or tilted to cause the airflow from each into almost any desired direction. When assembled together, the fan system may include any reasonable number of fan units stacked one atop another, and may be configured to rest on a floor or tabletop, or may be mounted to a vertical wall. When used together, the other fan units may all be powered through one of the fan units in master-slave fashion to enable the entire fan system to be powered from a single power outlet. When used together, the fan units may be individually tilted and rotated relative to one another in a variety of positions to direct airflows in a virtually infinite variety of arrangements.

In one embodiment, the invention may be practiced in an air blowing system including a bottom air blower having a bottom blower base and a bottom blower housing, a top air blower having a top blower base and a top blower housing tiltable relative thereto, and a removable coupling for enabling pivotable affixation of the top blower base to the bottom air blower, wherein the air blowing system has at least first and second operational modes. In the first operational mode, the removable coupling may not affix the top blower base to the bottom air blower and the bottom and top air blowers may be relatively independent, and in the second operational mode, the removable coupling may pivotably affix the top blower base to the bottom air blower.

The top and bottom air blowers may each include a power cord adapted for connection to a household power outlet for energizing the associated blower housing, and the bottom air blower may include a bottom power outlet. During the first mode, each power cord may be independently connected to a household power outlet, and during the second mode, the power cord of the bottom air blower may be connected to a household power outlet and the power cord of the top air blower may be connected to the bottom power outlet.

Each of the top and bottom blower bases may include a foot portion having two separated supports projecting upwardly there-from to form a yoke that defines a horizontal tilt axis, and each of the top and bottom blower housings may be tiltably affixed to the associated blower base at the horizontal tilt axis and be tiltable relative to the associated blower base thereabout.

Each of the top and bottom blower housings may include a motor driven axial fan blade for driving airflow through and from the associated blower housing. Each of the top and bottom air blowers may have a control for varying the airflow from the associated blower housing. The top and bottom air blowers may be substantially identical.

The removable coupling may be rigidly affable to an underside of the top blower base and include a round neck portion protruding downwardly to and pivotably receivable by a top side of the bottom blower housing. The top side of the bottom blower housing may include a locking screw for selectably engaging the coupling to allow or deny pivoting of the coupling to thereby allow or deny relative pivoting between the top and bottom air blowers.

The bottom blower base may be adapted for mounting to a vertical wall. The bottom blower base may be so adapted for mounting to a vertical wall by keyholes included in an underside thereof.

The bottom blower base may be tiltable rearwardly relative to the bottom blower housing into a semi-fixed angular position whereby a bottom edge of the bottom blower housing and a front edge of the bottom blower base lie on a horizontal resting plane when the bottom blower housing is substantially vertically disposed.

In another embodiment, the invention may be practiced in an air blowing system including a bottom air blower having a bottom blower base and a bottom blower housing, an intermediary air blower having an intermediary blower base and one or more intermediary blower housings, a top air blower having a top blower base and a top blower housing tiltable relative thereto, and a plurality of removable couplings for enabling pivotable affixation of the intermediary blower base to the bottom air blower and pivotable affixation of the top blower base to the intermediary air blower, wherein the air blowing system has at least first and second operational modes. In the first operational mode, none of the plurality of removable couplings affix the top blower base to the intermediary air blower or affix the intermediary blower base to the bottom air blower and the bottom, intermediary, and top air blowers may be relatively independent, and in the second operational mode, one of the plurality of removable couplings pivotably may affix the top blower base to the intermediary air blower and another of the plurality of removable couplings may pivotably affix the intermediary blower base to the bottom air blower.

The top, intermediary, and bottom air blowers may each include a power cord adapted for connection to a household power outlet for energizing the associated blower housing, the bottom air blower may include a bottom power outlet, and the intermediary air blower may include an intermediary power outlet. During the first mode, each power cord may be independently connected to a household power outlet, and during the second mode, the power cord of the bottom air blower may be connected to a household power outlet, the power cord of the intermediary air blower may be connected to the bottom power outlet, and the power cord of the top air blower may be connected to the intermediary power outlet.

Each of the top, intermediary, and bottom blower bases may include a foot portion having two separated supports projecting upwardly there-from to form a yoke that defines a horizontal tilt axis, and each of the top, intermediary, and bottom blower housings may be tiltably affixed to the associated blower base at the horizontal tilt axis and may be tiltable relative to the associated blower base thereabout.

Each of the top, intermediary, and bottom blower housings may include a motor driven axial fan blade for driving airflow through and from the associated blower housing. Each of the top, intermediary, and bottom air blowers may have a control for varying the airflow from the associated blower housing. The top, intermediary, and bottom air blowers may be substantially identical.

One of the plurality of removable couplings coupling may be rigidly affixable to an underside of the top blower base and may include a round neck portion protruding downwardly to and pivotably receivable by a top side of the intermediary blower housing, and another of the plurality of removable couplings coupling may be rigidly affixable to an underside of the intermediary blower base and may include a round neck portion protruding downwardly to and pivotably receivable by a top side of the bottom blower housing. The top sides of the bottom blower housing and the intermediary blower housing both may include a locking screw for selectably engaging the associated coupling to allow or deny pivoting of the associated coupling to thereby allow or deny relative pivoting between the associated air blowers. The bottom blower base may be adapted for mounting to a vertical wall.

The bottom blower base may be tiltable rearwardly relative to the bottom blower housing into a semi-fixed angular position whereby a bottom edge of the bottom blower housing and a front edge of the bottom blower base lie on a horizontal resting plane when the bottom blower housing is substantially vertically disposed.

In another embodiment, the invention may be practiced in an air blowing system including substantially identical first and second air blowers. Each of the blowers may include a base including a foot portion with two separated supports projecting upwardly there-from to form a yoke that defines a horizontal tilt axis. Each of the blowers may include a blower housing tiltably affixed to the base at and tiltable relative to the base about the horizontal tilt axis, and including an axial fan having a fan blade driven by an electric motor when energized for forcing airflow through and from the blower housing. Each of the blowers may include a NEMA-type power cord, a control switch electrically disposed between the power cord and the electric motor for selectably allowing or denying energy to the electric motor, a NEMA-type power outlet electrically connected to the power cord. The air blowing system may also include a removable coupling selectably affixable to an upper portion of the first air blower and a lower portion of the second air blower for enabling selectable pivotable connection of the first and second air blowers such that the air blowing system has first and second operational modes.

In the first operational mode, the coupling may be removed and may not affix the first and second air blowers, and the first and second air blowers may be relatively independently operable by connecting the power cords to different NEMA-type power supply outlets. And in the second operational mode, the removable coupling may connect the upper portion of the first air blower to the lower portion of the second air blower and the power cord of the second air blower may be connected to the power outlet of the first air blower and the air blowers may thereby cooperate to form a single air blowing assembly having two distinct airflows selectable directable in different directions.

Additional aspects of the invention may be appreciated upon perusal of the following detailed description of exemplary axial fan systems according to the invention along with the accompanying drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the invention. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a stackable fan system in accordance with a first exemplary embodiment of the invention, having a pair of identical fan units stacked together in the second operational mode and both pointed forwardly;

FIG. 2 is a right side view of the stackable fan system of FIG. 1;

FIG. 3 is a right side view of a stackable fan system in accordance with a second exemplary embodiment of the invention, having three of fan units all pointed forwardly;

FIG. 4 is a perspective view of the stackable fan system of FIG. 1 having the upper fan unit rotated relative to the base fan unit;

FIG. 5 is a front view of the stackable fan system of FIG. 1 having the upper fan unit tilted upwardly;

FIG. 6 is a right side view of the stackable fan system of FIG. 1 having the upper fan unit tilted upwardly;

FIG. 7 is a front view of the stackable fan system of FIG. 1 having a pair of fan units both pointed forwardly;

FIG. 8 is a front view of the stackable fan system of FIG. 3 having the three fan units both pointed forwardly;

FIG. 9 is a front view of the stackable fan system in accordance with a third exemplary embodiment of the invention having three fan units both pointed forwardly;

FIG. 10 is a right side view of the stackable fan system of FIG. 1 mounted to a vertical wall;

FIG. 11 is a right side view of the stackable fan system of FIG. 1 mounted to a vertical wall and having the upper fan unit tilted upwardly;

FIG. 12 is a right side view of the stackable fan system of FIG. 1 mounted to a vertical wall and having the upper fan unit rotated relative to the base fan unit;

FIG. 13 is a rear view of the stackable fan system of FIG. 1;

FIG. 14 is a top view of the stackable fan system of FIG. 1 having the upper fan unit rotated slightly rightwardly relative to the base fan unit;

FIG. 15 is a top view of the stackable fan system of FIG. 1 having the upper fan unit rotated more rightwardly relative to the base fan unit;

FIG. 16 is a top view of the stackable fan system of FIG. 1 having the upper fan unit rotated slightly leftwardly relative to the base fan unit;

FIG. 17 is a top view of the stackable fan system of FIG. 1 having the upper fan unit rotated more leftwardly relative to the base fan unit;

FIG. 18 is a cross-sectional view through the coupling position of the stackable fan systems of FIGS. 1, 3, and 9;

FIG. 19 is a bottom view of the stackable fan system of FIG. 1;

FIG. 20 is a bottom view of a stackable fan system in accordance with a fourth exemplary embodiment of the invention;

FIG. 21 is a perspective view of the stackable fan system of FIG. 1 in the first operational mode as a pair of identical independent fans;

FIG. 22 is a detailed view of the coupling of the stackable fan system of FIG. 1;

FIG. 23 is a perspective view of the stackable fan system of FIG. 1 in an alternate resting position; and

FIG. 24 is a side view of the stackable fan system of FIG. 1 in the alternate resting position.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1, 2, 4 through 7, and 10 through 24 illustrate a first exemplary embodiment of an air blowing system 100 including substantially identical first and second air blowers, 102B and 102T respectively. Each of the blowers includes a base 104 including a foot portion 106 with two separated supports, 108L and 108R, projecting upwardly there-from to form a yoke that defines a horizontal tilt axis 110. Each of the blowers includes a blower housing 112 tiltably affixed to the base at and tiltable relative to the base about the horizontal tilt axis, and including an axial fan 114 having a fan blade driven by an electric motor when energized for forcing airflow through and from the blower housing.

Each of the blowers includes a NEMA-type power cord 116 suited to plug into and connect with a standard NEMA-type wall outlet or extension cord (see any reference source for standard NEMA plug and outlet configurations, such as http://www.nooutage.com/nema_configurations.htm) for supplying energy to the system. A control switch 118 is electrically disposed between the power cord and the electric motor for selectably allowing or denying energy to the electric motor and varying the motor's rotational speed. And a NEMA-type power outlet 120 is integrated into the top of each blower and electrically connected to the blower's power cord such that the blower's outlet is live whenever its power cord is plugged into the wall outlet or extension cord. In non NEMA regions, equivalent power cords and outlets are be substituted.

The two blowers may be used individually or simultaneously but separately as complete and independent fans in what will be referred to as a “first operational mode”. In this first operational mode, as depicted in FIG. 21, the power cord of the one or both blowers to be used is plugged into the same or separate wall outlets 200 and the control switch of the one or both is turned to any of several selectable rotational speeds. The motor of the one or both is thereby energized to rotate the associated fan blade according to the selected speed and produce an airflow of the selected intensity. The fans may be used in separate rooms or used in the same room to provide two cooling airflows in different locations or to direct two air flows towards the same point from different locations. Each fan can, of course, be set to operate at a different speed, and each fan can be independently turned and tilted to select the desired airflow direction.

Each blower has a threaded hole 126 into its underside 128. As best seen in FIGS. 18 and 22, a removable coupling 130 is selectably affixable into the underside by screwing a threaded top portion 132 of the coupling into the threaded hole of the second blower until the flange 134 of the coupling seats firmly against the underside. Each blower also has a round hole 140 into its top side 142 which may receive a cylindrical lower portion 136 of the coupling. A locking screw 144 is threaded through the top side to selectably engage a groove 146 in the cylindrical lower portion.

When the coupling is threaded into the underside of the second or “top” blower 102T and the coupling's lower portion is fitted down into the round hole of the first or “bottom” blower, and the thumbscrew of the bottom blower is at least partially screwed into the coupling's groove, and when the power cord 116 of the top blower is plugged into the power outlet 120 of the bottom blower, the two blowers and coupling form the stacked blower system of FIGS. 1, 2, 4 through 7 and 10 through 20, in what will be referred to as the “second operational mode”.

In this “second operational mode”, the two blower units are assembled together to from a single blower unit capable of providing two airflows in a variety of different manners with each having distinct, differently directable, and independently controllable airflows, while obtaining power from a single wall outlet or extension cord.

Both blowers are tiltable relative to their respective bases so that the upward or downward slope of the airflow from each blower may be adjusted as desired, at the same or different slopes. The assembly may be rotated as a whole to adjust the horizontal direction of the bottom blowers' airflow, and the top blow may be rotated relative to the bottom blower by the pivotable fit of the coupling's lower portion into the bottom blower's top hole. Optional tightening of the lockscrew until it seats fully into the coupling's groove and securely against the coupling pivotally locks the two blowers in the existing pivotal relationship.

With the power cord of the top blower plugged into the lower blower's power outlet, the first or bottom blower becomes a “master” blower and the second or top blower becomes a “slave” blower, wherein only the bottom blower needs to be plugged into a wall outlet or extension cord to provide power to the entire assembly, thereby reducing the number of available wall outlets of extension cords that must be occupied.

Referring to FIGS. 23 and 24, and alternate resting position is shown for the air blowing system. In this configuration, the base of the bottom blower is pivoted rearwardly relative to the blower's housing. A ratcheting mechanism within the joint that affixes the housing to the base causes the base and housing to snap between numerous distinct semi-fixed angular relationships. By “semi-fixed”, it is meant that the base will rigidly maintain the position relative to the housing unless a substantial force is exerted to overcome the holding forces of the ratcheting mechanism. These angular positions include the semi-fixed position depicted, which is found to provide improved anti-tipover stability of the blowers compared to the arrangement of FIGS. 1 and 2, especially when the blowers are stacked together. This is because the footprint of the assembly is enlarged by this arrangement compared to that shown in FIGS. 1 and 2.

The blowers may alternatively be mounted to a vertical wall in either the first or second operational modes. As shown in FIG. 19, the underside 128 includes keyholes 150 which are intended to receive nail heads or screw heads (not shown) protruding from a wall 300 so that the base of the independent blowers in the first operational mode or base of the bottom blower in the second operational mode may be attached against the wall. FIGS. 10 through 12 show that the selectable directability of the airflows is still available in the wall mounted disposition. FIG. 20 shows an alternate version of screw or nail hanging openings 152 in the underside.

FIGS. 14 through 17 are top views of the assembly in the second operational mode to demonstrate the relative pivotability of the two blowers when stacked together.

Referring to FIGS. 3, 8, and 9, it can be appreciated that the system is adaptable to using any reasonable number of intermediary blowers; single intermediary blower 102M of the three-blower system 400 of FIGS. 3 and 8 or multiple intermediary blowers 102X of the multi-blower system 500 FIG. 9. In such arrangements, one additional coupling is used for each intermediary blower added; each attached the same as shown in FIG. 18.

From the foregoing, it will be clear that the present invention has been shown and described with reference to a preferred embodiment that merely exemplifies the broader invention revealed herein. Certainly, those skilled in the art can conceive of alternative embodiments. For instance, those with the major features of the invention in mind could craft embodiments that incorporate one or more major features while not incorporating all aspects of the foregoing exemplary embodiment.

Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is to be understood, therefore, that the invention can be practiced otherwise than as specifically described. With this in mind, the claims that follow will define the scope of protection to be afforded the invention, and those claims shall be deemed to include equivalent constructions insofar as they do not depart from the spirit and scope of the present invention. Certain of these claims may express certain elements as a means for performing a specific function, at times without the recital of structure or material. As the law demands, any such claims shall be construed to cover not only the corresponding structure and material expressly described in the specification but also equivalents thereof. 

We claim:
 1. An air blowing system comprising: a bottom air blower having a bottom blower base and a bottom blower housing; a top air blower having a top blower base and a top blower housing tiltable relative thereto; a removable coupling for enabling pivotable affixation of the top blower base to the bottom air blower; wherein the air blowing system has at least first and second operational modes, whereby; in the first operational mode, the removable coupling does not affix the top blower base to the bottom air blower and the bottom and top air blowers are relatively independent; and in the second operational mode, the removable coupling pivotably affixes the top blower base to the bottom air blower.
 2. The air blowing system of claim 1 wherein; the top and bottom air blowers each comprise a power cord adapted for connection to a household power outlet for energizing the associated blower housing; and the bottom air blower comprises a bottom power outlet; wherein during the first mode, each power cord is independently connectable to a household power outlet; and during the second mode, the power cord of the bottom air blower is connectable to a household power outlet and the power cord of the top air blower is connectable to the bottom power outlet.
 3. The air blowing system of claim 2 wherein each of the top and bottom blower bases comprises a foot portion having two separated supports projecting upwardly there-from to form a yoke that defines a horizontal tilt axis, and wherein each of the top and bottom blower housings is tiltably affixed to the associated blower base at the horizontal tilt axis and is tiltable relative to the associated blower base thereabout.
 4. The air blowing system of claim 3 wherein each of the top and bottom blower housings comprises a motor driven axial fan blade for driving airflow through and from the associated blower housing.
 5. The air blowing system of claim 4 wherein each of the top and bottom air blowers has a control for varying the airflow from the associated blower housing.
 6. The air blowing system of claim 5 wherein the top and bottom air blowers are substantially identical.
 7. The air blowing system of claim 6 wherein the removable coupling is rigidly affixable to an underside of the top blower base and comprises a round neck portion protruding downwardly to and pivotably receivable by a top side of the bottom blower housing.
 8. The air blowing system of claim 7 wherein the top side of the bottom blower housing comprises a locking screw for selectably engaging the coupling to allow or deny pivoting of the coupling to thereby allow or deny relative pivoting between the top and bottom air blowers.
 9. The air blowing system of claim 1 wherein the bottom blower base is adapted for mounting to a vertical wall.
 10. The air blowing system of claim 9 wherein the bottom blower base is so adapted for mounting to a vertical wall by keyholes comprised in an underside thereof.
 11. The air blowing system of claim 1 wherein the bottom blower base is tiltable rearwardly relative to the bottom blower housing into a semi-fixed angular position whereby a bottom edge of the bottom blower housing and a front edge of the bottom blower base lie on a horizontal resting plane when the bottom blower housing is substantially vertically disposed.
 12. An air blowing system comprising: a bottom air blower having a bottom blower base and a bottom blower housing; an intermediary air blower having an intermediary blower base and one or more intermediary blower housings; a top air blower having a top blower base and a top blower housing tiltable relative thereto; a plurality of removable couplings for enabling pivotable affixation of the intermediary blower base to the bottom air blower and pivotable affixation of the top blower base to the intermediary air blower; wherein the air blowing system has at least first and second operational modes, whereby; in the first operational mode, none of the plurality of removable couplings affix the top blower base to the intermediary air blower or affix the intermediary blower base to the bottom air blower and the bottom, intermediary, and top air blowers are relatively independent; and in the second operational mode, one of the plurality of removable couplings pivotably affixes the top blower base to the intermediary air blower and another of the plurality of removable couplings pivotably affixes the intermediary blower base to the bottom air blower.
 13. The air blowing system of claim 12 wherein; the top, intermediary, and bottom air blowers each comprise a power cord adapted for connection to a household power outlet for energizing the associated blower housing; the bottom air blower comprises a bottom power outlet; and the intermediary air blower comprises an intermediary power outlet; wherein during the first mode, each power cord is independently connectable to a household power outlet; and during the second mode, the power cord of the bottom air blower is connectable to a household power outlet, the power cord of the intermediary air blower is connectable to the bottom power outlet, and the power cord of the top air blower is connectable to the intermediary power outlet.
 14. The air blowing system of claim 13 wherein each of the top, intermediary, and bottom blower bases comprises a foot portion having two separated supports projecting upwardly there-from to form a yoke that defines a horizontal tilt axis, and wherein each of the top, intermediary, and bottom blower housings is tiltably affixed to the associated blower base at the horizontal tilt axis and is tiltable relative to the associated blower base thereabout.
 15. The air blowing system of claim 14 wherein each of the top, intermediary, and bottom blower housings comprises a motor driven axial fan blade for driving airflow through and from the associated blower housing.
 16. The air blowing system of claim 15 wherein each of the top, intermediary, and bottom air blowers has a control for varying the airflow from the associated blower housing.
 17. The air blowing system of claim 16 wherein the top, intermediary, and bottom air blowers are substantially identical.
 18. The air blowing system of claim 17 wherein one of the plurality of removable couplings coupling is rigidly affixable to an underside of the top blower base and comprises a round neck portion protruding downwardly to and pivotably receivable by a top side of the intermediary blower housing, and another of the plurality of removable couplings coupling is rigidly affixable to an underside of the intermediary blower base and comprises a round neck portion protruding downwardly to and pivotably receivable by a top side of the bottom blower housing.
 19. The air blowing system of claim 18 wherein the top sides of the bottom blower housing and the intermediary blower housing both comprise a locking screw for selectably engaging the associated coupling to allow or deny pivoting of the associated coupling to thereby allow or deny relative pivoting between the associated air blowers.
 20. The air blowing system of claim 12 wherein the bottom blower base is adapted for mounting to a vertical wall.
 21. The air blowing system of claim 12 wherein the bottom blower base is tiltable rearwardly relative to the bottom blower housing into a semi-fixed angular position whereby a bottom edge of the bottom blower housing and a front edge of the bottom blower base lie on a horizontal resting plane when the bottom blower housing is substantially vertically disposed.
 22. An air blowing system comprising: substantially identical first and second air blowers each having; a base comprising a foot portion with two separated supports projecting upwardly there-from to form a yoke that defines a horizontal tilt axis, a blower housing tiltably affixed to the base at and tiltable relative to the base about the horizontal tilt axis, and comprising an axial fan having a fan blade driven by an electric motor when energized for forcing airflow through and from the blower housing; a NEMA-type power cord; a control switch electrically disposed between the power cord and the electric motor for selectably allowing or denying energy to the electric motor; a NEMA-type power outlet electrically connected to the power cord; and a removable coupling selectably affixable to an upper portion of the first air blower and a lower portion of the second air blower for enabling selectable pivotable connection of the first and second air blowers such that the air blowing system has first and second operational modes; whereby in the first operational mode, the coupling is removed and does not affix the first and second air blowers, and the first and second air blowers are relatively independently operable by connecting the power cords to different NEMA-type power supply outlets; and in the second operational mode, the removable coupling connects the upper portion of the first air blower to the lower portion of the second air blower and the power cord of the second air blower is connected to the power outlet of the first air blower and the air blowers thereby cooperate to form a single air blowing assembly having two distinct airflows selectable directable in different directions. 